1 // readsyms.cc -- read input file symbols for gold
3 // Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21 // MA 02110-1301, USA.
29 #include "dirsearch.h"
40 // If we fail to open the object, then we won't create an Add_symbols
41 // task. However, we still need to unblock the token, or else the
42 // link won't proceed to generate more error messages. We can only
43 // unblock tokens when the workqueue lock is held, so we need a dummy
44 // task to do that. The dummy task has to maintain the right sequence
45 // of blocks, so we need both this_blocker and next_blocker.
47 class Unblock_token : public Task
50 Unblock_token(Task_token* this_blocker, Task_token* next_blocker)
51 : this_blocker_(this_blocker), next_blocker_(next_blocker)
56 if (this->this_blocker_ != NULL)
57 delete this->this_blocker_;
63 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
64 return this->this_blocker_;
69 locks(Task_locker* tl)
70 { tl->add(this, this->next_blocker_); }
78 { return "Unblock_token"; }
81 Task_token* this_blocker_;
82 Task_token* next_blocker_;
85 // Class read_symbols.
87 Read_symbols::~Read_symbols()
89 // The this_blocker_ and next_blocker_ pointers are passed on to the
93 // Return whether a Read_symbols task is runnable. We can read an
94 // ordinary input file immediately. For an archive specified using
95 // -l, we have to wait until the search path is complete.
98 Read_symbols::is_runnable()
100 if (this->input_argument_->is_file()
101 && this->input_argument_->file().may_need_search()
102 && this->dirpath_->token()->is_blocked())
103 return this->dirpath_->token();
108 // Return a Task_locker for a Read_symbols task. We don't need any
112 Read_symbols::locks(Task_locker*)
116 // Run a Read_symbols task.
119 Read_symbols::run(Workqueue* workqueue)
121 // If we didn't queue a new task, then we need to explicitly unblock
123 if (!this->do_read_symbols(workqueue))
124 workqueue->queue_soon(new Unblock_token(this->this_blocker_,
125 this->next_blocker_));
128 // Open the file and read the symbols. Return true if a new task was
129 // queued, false if that could not happen due to some error.
132 Read_symbols::do_read_symbols(Workqueue* workqueue)
134 if (this->input_argument_->is_group())
136 gold_assert(this->input_group_ == NULL);
137 this->do_group(workqueue);
141 Input_file* input_file = new Input_file(&this->input_argument_->file());
142 if (!input_file->open(this->options_, *this->dirpath_, this))
145 // Read enough of the file to pick up the entire ELF header.
147 off_t filesize = input_file->file().filesize();
151 gold_error(_("%s: file is empty"),
152 input_file->file().filename().c_str());
156 int read_size = elfcpp::Elf_sizes<64>::ehdr_size;
157 if (filesize < read_size)
158 read_size = filesize;
160 const unsigned char* ehdr = input_file->file().get_view(0, 0, read_size,
163 if (read_size >= Archive::sarmag)
166 = memcmp(ehdr, Archive::armagt, Archive::sarmag) == 0;
168 || memcmp(ehdr, Archive::armag, Archive::sarmag) == 0)
170 // This is an archive.
171 Archive* arch = new Archive(this->input_argument_->file().name(),
172 input_file, is_thin_archive,
173 this->dirpath_, this);
174 arch->setup(this->input_objects_);
176 // Unlock the archive so it can be used in the next task.
179 workqueue->queue_next(new Add_archive_symbols(this->symtab_,
181 this->input_objects_,
186 this->next_blocker_));
191 if (parameters->options().has_plugins())
193 Pluginobj* obj = parameters->options().plugins()->claim_file(input_file,
197 // The input file was claimed by a plugin, and its symbols
198 // have been provided by the plugin.
200 // We are done with the file at this point, so unlock it.
203 workqueue->queue_next(new Add_symbols(this->input_objects_,
208 this->next_blocker_));
215 static unsigned char elfmagic[4] =
217 elfcpp::ELFMAG0, elfcpp::ELFMAG1,
218 elfcpp::ELFMAG2, elfcpp::ELFMAG3
220 if (memcmp(ehdr, elfmagic, 4) == 0)
222 // This is an ELF object.
224 Object* obj = make_elf_object(input_file->filename(),
225 input_file, 0, ehdr, read_size);
229 Read_symbols_data* sd = new Read_symbols_data;
230 obj->read_symbols(sd);
232 // Opening the file locked it, so now we need to unlock it.
233 // We need to unlock it before queuing the Add_symbols task,
234 // because the workqueue doesn't know about our lock on the
235 // file. If we queue the Add_symbols task first, it will be
236 // stuck on the end of the file lock, but since the
237 // workqueue doesn't know about that lock, it will never
238 // release the Add_symbols task.
240 input_file->file().unlock(this);
242 // We use queue_next because everything is cached for this
243 // task to run right away if possible.
245 workqueue->queue_next(new Add_symbols(this->input_objects_,
246 this->symtab_, this->layout_,
249 this->next_blocker_));
255 // Queue up a task to try to parse this file as a script. We use a
256 // separate task so that the script will be read in order with other
257 // objects named on the command line. Also so that we don't try to
258 // read multiple scripts simultaneously, which could lead to
259 // unpredictable changes to the General_options structure.
261 workqueue->queue_soon(new Read_script(this->options_,
265 this->input_objects_,
268 this->input_argument_,
271 this->next_blocker_));
275 // Handle a group. We need to walk through the arguments over and
276 // over until we don't see any new undefined symbols. We do this by
277 // setting off Read_symbols Tasks as usual, but recording the archive
278 // entries instead of deleting them. We also start a Finish_group
279 // Task which runs after we've read all the symbols. In that task we
280 // process the archives in a loop until we are done.
283 Read_symbols::do_group(Workqueue* workqueue)
285 Input_group* input_group = new Input_group();
287 const Input_file_group* group = this->input_argument_->group();
288 Task_token* this_blocker = this->this_blocker_;
290 for (Input_file_group::const_iterator p = group->begin();
294 const Input_argument* arg = &*p;
295 gold_assert(arg->is_file());
297 Task_token* next_blocker = new Task_token(true);
298 next_blocker->add_blocker();
299 workqueue->queue_soon(new Read_symbols(this->options_,
300 this->input_objects_,
301 this->symtab_, this->layout_,
302 this->dirpath_, this->mapfile_,
304 this_blocker, next_blocker));
305 this_blocker = next_blocker;
308 const int saw_undefined = this->symtab_->saw_undefined();
309 workqueue->queue_soon(new Finish_group(this->input_objects_,
316 this->next_blocker_));
319 // Return a debugging name for a Read_symbols task.
322 Read_symbols::get_name() const
324 if (!this->input_argument_->is_group())
326 std::string ret("Read_symbols ");
327 if (this->input_argument_->file().is_lib())
329 ret += this->input_argument_->file().name();
333 std::string ret("Read_symbols group (");
334 bool add_space = false;
335 const Input_file_group* group = this->input_argument_->group();
336 for (Input_file_group::const_iterator p = group->begin();
342 ret += p->file().name();
348 // Class Add_symbols.
350 Add_symbols::~Add_symbols()
352 if (this->this_blocker_ != NULL)
353 delete this->this_blocker_;
354 // next_blocker_ is deleted by the task associated with the next
358 // We are blocked by this_blocker_. We block next_blocker_. We also
362 Add_symbols::is_runnable()
364 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
365 return this->this_blocker_;
366 if (this->object_->is_locked())
367 return this->object_->token();
372 Add_symbols::locks(Task_locker* tl)
374 tl->add(this, this->next_blocker_);
375 tl->add(this, this->object_->token());
378 // Add the symbols in the object to the symbol table.
381 Add_symbols::run(Workqueue*)
383 Pluginobj* pluginobj = this->object_->pluginobj();
384 if (pluginobj != NULL)
386 this->object_->add_symbols(this->symtab_, this->sd_, this->layout_);
390 if (!this->input_objects_->add_object(this->object_))
392 // FIXME: We need to close the descriptor here.
393 delete this->object_;
397 this->object_->layout(this->symtab_, this->layout_, this->sd_);
398 this->object_->add_symbols(this->symtab_, this->sd_, this->layout_);
399 this->object_->release();
405 // Class Finish_group.
407 Finish_group::~Finish_group()
409 if (this->this_blocker_ != NULL)
410 delete this->this_blocker_;
411 // next_blocker_ is deleted by the task associated with the next
412 // input file following the group.
415 // We need to wait for THIS_BLOCKER_ and unblock NEXT_BLOCKER_.
418 Finish_group::is_runnable()
420 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
421 return this->this_blocker_;
426 Finish_group::locks(Task_locker* tl)
428 tl->add(this, this->next_blocker_);
431 // Loop over the archives until there are no new undefined symbols.
434 Finish_group::run(Workqueue*)
436 int saw_undefined = this->saw_undefined_;
437 while (saw_undefined != this->symtab_->saw_undefined())
439 saw_undefined = this->symtab_->saw_undefined();
441 for (Input_group::const_iterator p = this->input_group_->begin();
442 p != this->input_group_->end();
445 Task_lock_obj<Archive> tl(this, *p);
447 (*p)->add_symbols(this->symtab_, this->layout_,
448 this->input_objects_, this->mapfile_);
452 // Delete all the archives now that we no longer need them.
453 for (Input_group::const_iterator p = this->input_group_->begin();
454 p != this->input_group_->end();
457 delete this->input_group_;
462 Read_script::~Read_script()
464 if (this->this_blocker_ != NULL)
465 delete this->this_blocker_;
466 // next_blocker_ is deleted by the task associated with the next
470 // We are blocked by this_blocker_.
473 Read_script::is_runnable()
475 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
476 return this->this_blocker_;
480 // We don't unlock next_blocker_ here. If the script names any input
481 // files, then the last file will be responsible for unlocking it.
484 Read_script::locks(Task_locker*)
488 // Read the script, if it is a script.
491 Read_script::run(Workqueue* workqueue)
493 bool used_next_blocker;
494 if (!read_input_script(workqueue, this->options_, this->symtab_,
495 this->layout_, this->dirpath_, this->input_objects_,
496 this->mapfile_, this->input_group_,
497 this->input_argument_, this->input_file_,
498 this->next_blocker_, &used_next_blocker))
500 // Here we have to handle any other input file types we need.
501 gold_error(_("%s: not an object or archive"),
502 this->input_file_->file().filename().c_str());
505 if (!used_next_blocker)
507 // Queue up a task to unlock next_blocker. We can't just unlock
508 // it here, as we don't hold the workqueue lock.
509 workqueue->queue_soon(new Unblock_token(NULL, this->next_blocker_));
513 // Return a debugging name for a Read_script task.
516 Read_script::get_name() const
518 std::string ret("Read_script ");
519 if (this->input_argument_->file().is_lib())
521 ret += this->input_argument_->file().name();
525 } // End namespace gold.